RheumNow: The Ill-Conceived Diagnosis of Fibromyalgia

Where fibromyalgia diagnosis can go wrong, and how to get it right

I'm always amazed at how often fibromyalgia (FM) is either misdiagnosed or not diagnosed. Studies of outpatient rheumatology services have shown that FM is one of the top two or three diagnoses for new consultations.

New patients with a history of FM almost always have FM. Such cannot be said for those presenting with a history of lupus, rheumatoid arthritis (RA), etc. Why is it that many physicians never diagnose FM and instead mistakenly label patients as having lupus, spondyloarthropathy, or RA?

More surprising is the patient with chronic pain, myalgias, arthralgias, fatigue, and a sleep disturbance and there is no consideration of FM.

I can best address this problem by offering up my clues for the diagnosis of FM. But, before I launch my "tips" on this facile diagnosis, let it be known that: 1) I am certain that FM is a real, diagnosable pain amplification disorder; 2) I see and care for patients with FM; 3) I have an evidence based plan for FM treatment; and 4) patients with inflammatory disorders (lupus, RA, Sjogrens) may also have FM, myofascial pain, and sleep-related musculoskeletal pain.

The diagnosis of FM can be based on the 1990 ACR criteria by Wolfe and colleagues requiring widespread pain and >11 of 18 tender points. Or you could go by the 2010 ACR revised criteria that give more importance to patient symptoms rather than tender points and results in a complex calculation of a widespread pain index (WPI) and symptom severity (SS) scores.

While these are helpful for research and clinical trials, I prefer a practical definition of FM. The diagnosis of FM requires widespread soft tissue pain and tenderness, the lack of inflammatory or degenerative findings, and supportive features of fatigue, poor sleep, dysesthesias, and spasmodic complaints (including headache, migraine, TMJ pain, PMS, spastic bladder, or irritable bowel syndrome).

Yet 30 years of practice and thousands of consults have shown me other distinctive clues that heavily weigh in favor of a FM diagnosis. The following are predictive enough to encourage consideration of FM (although there may be exceptions to these "rules").

Globally positive review of symptoms: if you use a survey form for intake of new patients, you can be sure that anyone who checks more than 20 boxes (symptoms) will have FM. This is also known as a positive organ recital.

Notalgia: this is a term I invented to identify patients who bring so many notes to the visit that you hurt! This includes too much ink on the page and 4 minute answers to a yes/no question. This indicates the patient's inability to prioritize complaints, issues, and findings -- hence they are all important.

Multiple Chemical Sensitivities: patients with several or many drug, chemical, or environmental sensitivities (this is driven by their extremely low pain thresholds).

"I just don't like taking medicines": while this may be said and may be true, FM patients tend to overuse health care services, see numerous consultants (seeking a correct diagnosis) and are given numerous add-on prescriptions and therapies.

MSK symptoms in women with a history of augmentation mammoplasty or depression. One colleague used to refer to this constellation with the non-codeable term "psychoboobalgia".

Fibromyalgia should be suspected first in patients with MSK symptoms and a background psychiatric disorder.

Lyme disease in Texas: there is no Lyme disease in Texas (or other nonendemic states), yet there are many patients with MSK symptoms and abnormal but poorly sensitive Lyme (and other) serologies.

Hospitalized 6 weeks ago but still wearing their hospital ID bracelet: This falls under strange behavior, thus, MSK symptoms and strange behavior should lead to a consideration of FM.

Exaggerated pain responses on exam: best described as "folds like a $20 card table when you touch them."

Multiple autoimmune/inflammatory disorders: while it is possible that two autoimmune conditions (e.g., lupus, RA, gout, ankylosing spondylitis, Hashimoto's thyroiditis, Sjogren's syndrome, Behcets, interstitial cystitis) may exist in the same person -- it is infinitely more likely that one or both of these is the wrong diagnosis and that FM may instead be the right diagnosis.

Curiously, those with delayed pain responses. By this I mean that when doing an orderly joint exam, the patient who admits to pain in the joint you touched 3-5 joints ago is most likely to have FM. (It should also go without saying that a patient who has a TJC >20 joints is also likely to have FM.)

For those who do practice metrics, like CDAI, SDA, RAPID3, or GAS, on their RA or on all MSK patients -- a score of greater than 30 almost always involves primary or secondary FM as a treatable cause.

Lastly the most obvious and most common scenario is the patient with MSK symptoms, and a +ANA but no other criteria for lupus; this patient should be considered as possibly having FM.

In practice, finding any one of the above should lead to a detailed tender point exam, a joint exam (to exclude synovitis/effusion), and a detailed sleep history. If I diagnose FM as an alternative to their previous rheumatic diagnosis, patients may accept or refute FM as their diagnosis, or they may want an explanation for what their previous physician(s) said or did. Obviously, I cannot speak for the conversations, diagnoses, reports, and issues that occurred before me and I can only take ownership of the evidence and findings that exist today. Suffice it to say, a change in diagnosis is not always gleefully received. I find it helpful to use a patient handout on FM and explain the basis of why he/she has FM today and why "lupus" or "RA" is not an active problem today.

Jack Cush, MD, is the director of clinical rheumatology at the Baylor Research Institute and a professor of medicine and rheumatology at Baylor University Medical Center in Dallas. He is the executive editor of RheumNow.com. A version of this article first appeared on RheumNow, a news, information and commentary site dedicated to the field of rheumatology. Register to receive their free rheumatology newsletter.

Cush declared he has not received compensation as an advisor or consultant on this subject.

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